Artificial thread and method of making same



Sept. 1, 1936. p ALLES 2,053,123

ARTIFICIAL THREAD AND METHOD OF MAKING SAME Filed July 15, 1933 TQMW 62%,

ATTORNEY Patented Sept, 1, 1936 UNITED sTATEs PATENT OFFICE ARTIFICIAL THREAD AND METHOD or MAKING SAME Francis P. Alles, Buffalo, N. Y., assignor to Du Pont Rayon Company, New York, N. Y., a cor-.

poration of Delaware Application July 15, 1933, Serial No. 680,547

2 Claims. (Cl. 152-13) This invention relates to artificial thread and is combined as by being twisted together to conmore particularly to the manufacture of artistitute the thread 2. Short fibers 3 are secured ficial thread having a fuzzy surface. to the filaments in a manner hereafter more Artificial thread comprises a plurality of confully explained. These fibers, project from the 6 tinuous filaments twisted together. Each of the surface of the thread, constituting a nap, wherefilaments, and hence the ultimate thread, has a by a fuzzy surface is imparted to the thread. It smooth surface. These characteristics, though is to be noted that the thread is substantially highly desirable in many uses of the thread, uniformly interspersed or provided throughout render the thread or fabric produced therefrom its entire length with the short fibers. The twist 10 unsatisfactory for certain purposes. in the final thread, as well as the filament count 10 Prior to this invention, the above-mentioned and denierthereof, will, of course, depend on the limitations were sought to be overcome by roughultimate use of said thread. ening the surface of the artificial thread with The fibers 3 may be of any suitable material, an abrasive, to more or less abrade the surface such as short staple lengths of regenerated celluof the thread; by introducing in the spinning lose or cellulose derivative yarn, short lengths 15 solution solid particles which imparted an unof artificial straw, short cotton lint, shredded even surface to the yarn, and by irregularly wood pulp, cotton flock, etc., and of any suitspinning the solution, as by means of a pulsatable length and size. In the preferred embodiing pump, to produce a thread of varying denier. ment of the invention, short rayon staple lengths,

In each of these procedures, the irregular surface about 1/16 of an inch in length and having a 20 of the yarn was produced by sacrificing a highly denier varying from 1-8, are used. important characteristic, i. e. strength, and this There are several procedures of securing the obviously was a very serious defect. short fibers 3 to the ultimate yarn. In general,

I have found that I can overcome the restricthe process comprises applying the short fibers tive limitations of the smooth-surfaced artificial to the rayon filaments and then securing the said 25 thread by applying short fibers to the continuous fibers in position in the final thread. rayon filaments, preferably prior to or simultane- In one embodiment of the method, a cellulosic ous with the combination of said filaments to solution, such as a viscose solution, is spun in produce the final yarn, whereby a yarn having the-usual manner into a bath containing the a fuzzy surface is produced without sacrificing short fibers dispersed therethrough. As the 30 the strength of the final yarn. thread passes through the spinning bath, the

It is, therefore, an object of this invention to fibers are picked up thereby and are firmly seproduce an artificial thread formed of a plurality cured to the thread by the normal convergence of continuous rayon filaments combined together of the filaments or by twisting.

5 and havi a. fuzzy surface, the latter being se- In another embodiment of the process consticured by short fibers projecting from the surface tuting the invention, a plurality of untwisted conthereof throughout the length of the thread. tinuous rayon filaments is passed through a bath Another object of this invention is to provide containing dispersed short fibers in such a way methods for producing the above-mentioned arthat the spread filaments pick up a certain tificial thread. amount of short fibers, depending inter alia upon Additional objects will appear from the followthe concentration of the dispersion. In this proing description, appended claims and accomcedure and other methods involving the use of panying drawing wherein: liquid mediums, it is advantageous to provide di- Figures 1, 2 and 3 are exaggerated and enrectional currents in the liquid, or otherwise agilarged perspective views, p y nded, of an tate the liquid, so as to cause the fibers to enter 45 artificial thread, strand and cord, respectively, between the filaments at right angles thereto. produced in accordance with the instant inven- Intermeshing in this manner is advantageous in tion. that the maximum benefit as regards adhesion, Figure 4 is a vertical section of a tire containing .more fully described hereafter, is secured with a a cord fabric made of cords prepared in accord-' minimum amount of fiber. 50 ance with this invention. Instead of applying short fibers to the filaments Referring now to the drawing, wherein like by passing the latter through a bath containing numer ls designate li e parts, and particularly the former, theuntwisted filaments maybepassed to Figure 1, the reference numeral I designates through a chamber having the short fibers susa continuous rayon filament, a plurality of which pended in the atmosphere thereof. During the 6 passage of the filaments through the chamber. the short fibers will adhere to the filaments and be secured in place by the subsequent twisting of the filaments to constitute the final thread.

In still another embodiment of the method, the short fibers are incorporated by twisting the thread in an atmosphere of these small fibers. In this operation, during ballooning of the thread, there occurs a separation of the individual filaments between which the short fibers are caught and later securely held by the tight twist imparted to the thread.

In certain cases it is advantageous to render the filaments or thread slightly tacky, through the use of a suitable adhesive, prlor or simultaneous with the application of the short fiber. Many adhesives may be used for this purpose. When the rayon thread consists of regenerated cellulose, any of the adhesives suitable for gluing cellulosic materials may be used for fixing the fiber, or, indeed, many of the usual sizing compositions may be employed. Generally, when an adhesive is used, it is of such a nature that it does not interfere with the properties of the yarn. Preferably, it is also of such a nature that it does not deleteriously affect the product in which the yarn is destined to be used. On the contrary, the adhesive, wherever possible, should be of such a nature that it has a special advantage and function in the final product. For example, if the thread is to be used in the reinforcing of rubber material, a dilute latex or rubber cement may be used to advantage as the adhesive.

It is to be understood that the invention hereinbefore described is not restricted to only an artificial thread having a fuzzy surface composed of a plurality of continuous rayon filaments twisted together. The instant invention is also capable of and adapted to be used in the production of rayon strands and cords having naps on the surface thereof. In order to more particularly explain this phase of the invention, it will be described in connection with. for example, the construction of cords, such as is used in the manufacture of cord fabrics for reinforcing vulcanized rubber materials, for example rubber tires.

In the construction of tire cords, it is customary to combine, by twisting together, five threads to form a strand, the twisting generally being in a direction opposite to that of the individual threads. Three of these strands are then combined, as by twisting, to produce the final cord. The twist in the final cord is usually in a direction opposite to the twist in the strands.

In accordance with the instant invention, the nap or fuzzy surface of the strands may be secured either by employing threads of the type previously described and illustrated in Figure 1,

- or by incorporating the fibers in the strands by any of the procedures described. The nap or fuzzy surface of the rayon cord may be secured in a manner comparable to that employed in connection with the production of rayon strands. For example, the rayon strands utilized in the cord may be of the fuzzy type Just described or, when smooth-surfaced rayon strands are used, the short fibers may be incorporated during the making of the cord from rayon strands in the same manner as used in the manufacture of the fuzzy surface thread. Likewise, a finished cord may be passed continuously through a device which momentarily opens up the cord and, while the cord is in this condition, the short fibers are interjected. The cord, upon the resumption ,of

its normal twist, binds the short fibers into the cord.

Referring now to Figure 2, which illustrates a rayon strand produced in accordance with this invention, the reference numeral 4 designates a rayon thread, five of which are combined, as by twisting in a direction opposite to that of the twist of the threads, to constitute the strand 5. Short fibers 6 of the type previously mentioned are secured to and preferably project from the surface of the strand, whereby a nap or fuzzy surface is provided for the strand. It is to be understood that the number of threads, denier and filament count of the thread, as well as the turns per inch in the strand, depend on the ultimate use of the strand. When the strand is to be used, for example, in the manufacture of cords for fabrics for reinforcing rubber materials, such as tires, the strand may have twenty turns per inch and'consist of five rayon threads, each of said threads being of 275 denierfilament, and having a twist of seven turns per inch.

Referring now to Figure 3, which illustrates a rayon cord produced in accordance with this invention, the reference numeral i designates a rayon strand, three of which are combined by twisting in a direction opposite to the twist in the strand. Short fibers 8 of the type previously mentioned are secured to and preferably project from the surface of the cord, whereby a nap or fuzzy surface is imparted thereto. It is to be understood that the number of strands and twists per inch in the final cord depend on the ultimate use of said cord. If the cord is to be used in the manufacture of cord fabrics for reinforcing rubber, such as tires, it may have a twist of ten turns per inch and may consist of three strands having twenty turns per inch, each strand consisting of five threads, and each of said threads being of 175 denier-120 filament, and having seven turns per inch.

In order to more fully explain the process, several illustrative examples are set forth:

Ezample I.Five viscose rayon threads, each of 275 denier-120 filament, are arranged in ribbon or conical form and passed at a speed of about fifteen inches per minute through a water bath containing 0.03 grams of 1 inch viscose rayon fibers per 100 cc. The water bath is slowly agitated to maintain the short fibers in suspension and prevent the settling thereof. As the threads pass through the bath, the fibers are caught therebetween and secured in place by tightly twisting the threads in the bath.

The strand formed in the manner .just described contains approximately 16% by weight of the short fibers.

The amount of short fibers can be varied to suit different conditions by changing the concentration thereof in the bath, the speed of agitation, or the rate of travel of the thread.

Example II .The procedure is the same as Example I, except that the speed of drawing the threads through the bath is inches per minute and the amount of fibers is 0.1 grams per 100 cc. The rate of agitation is increased.

Example III.--In addition to the procedure set forth in either Examples I or II, the dispersion containing the short fibers is also projected amongst the threads, as by pumping.

Example IV.-Same as Examples I, II or III.

except that the thread is drawn through the bath at a speed of 340 inches per minute and finally twisted on a ring twister of the type employed for wet twisting.

Example V.Same as Examples I and 11, except that the bath contains an adhesive, such as latex, gum arabic, dispersion of waxes, etc. When dispersions of waxes are used the product is dried at Ya sufliciently high temperature so that the adhesive is made flowable to form a continuous coating.

Example VI .-.-Same as Examples I, II and IV, except that the short fibers are' dispersed in an organic liquid, such as benzene, instead of water. The use of an organic liquid gives an operation which is equivalent to dry twisting.

Example VII Same as Example VI, except that the dispersion contains a water-insoluble adhesive.

Example VIII .-A viscose solution is spun in a spinning bath containing short length staple in a concentration of about 0.3 grams per 100 cc. As the filaments pass through the bath, the short staples are picked up thereby and are secured in position by the convergence of the filaments and the subsequent twisting.

Example IX.--Threads are twisted or doubled and twisted through an atmosphere of short fiber.

Example X.-Threads are drawn through a suitable adhesive to render them tacky and then through an atmosphere of the short fibers.

Example XI .In addition to the procedure set forth in Example X, the thread is twisted as it passes through the atmosphere containing short fibers or subsequently thereto.

'The thread, as above mentioned, has short fibers projecting therefrom constituting a nap 0r whisker and imparting a fuzzy surface thereto. When made into fabrics, by any of the wellknown procedures, there is produced a fabric having an unusual appearance and which is more elastic and resistant to creasing and crushing than fabrics of similar types produced from ordinary rayon threads. Moreover, the individual threads of the fabric will tend to stay in their proper places. I

The products of this invention, 1. e. threads,

' strands, cords or fabrics, are-admirably suitable for use in the production of laminated materials or as reinforcing elements for plastic compositions. By virtue of the fuzzy surface an exceedingly effective anchorage is secured.

Fabrics of the usual type, open mesh fabrics, scrim, etc., formed of the fuzzy threads herein described, may be laminated to almost any material by the aid of adhesives. They are particularly well adapted to be secured to those bases which bond to ordinary rayon thread to a slight degree.

In the artificial silk industry, some spinning buckets are made of a bakelite" composition reinforced with cotton or the like cloth. Fabrics formed of normal smooth-surfaced rayon could not be used because of the'inefltective bonding,

between them and the bakelite". However, a fabric made of the fuzzy artificial thread herein described can be used with great success. Similarly, when cord fabrics made of the yarn described in this application are used as reinforcing elements in vulcanized rubber materials, such as vehicle tires, belts, hose, etc., a greater degree of bonding is secured than when the corresponding smooth-surfaced rayon material was/used.

To secure a significant increase in anchorage, it is only necessary to use a moderate proportion of the short-fibers. Thus, the incorporation ina tire cord of 10% by weight of the short fibers increases the anchorage of the rayon cord to the rubber about 33%. Increases in the amount of the short fibers improves the anchorage proportionately. This is clearly shown bythe tabulation below:

Permntge .Anchora go of 1835 32 cord to rubber weight of 3 :32; gg g 1.52m 4 no! ment cord embedded o 11. o 4. o 13.0 a 0 1a a 9. 5 1a 7 1a 5 11. 1 20. 6 is. o 2i. 4 19. s 3% 3'3 When three of the strands of Example L-i'or example, are twisted together to form a cable, a cord is produced possessing 62% greater adhesion to rubber than the comparable smoothsurfaced cord.

The rayon contemplated by the instant invention is preferably of the regenerated cellulose type, though it is obvious that artificial thread formed of cellulose derivatives, such ascellulose acetate, cellulose ethers, etc., may be used. It is to be understood that the rayon used is suitable for the ultimate use of the product. Thus, if a cord made in accordance with this invention is to be fabrieatedlnto a cord fabric and used as a reinforcement for rubber materials, such as tires, hose, belts, etc., the rayon should be of high tenacity, such as, for example, described in the Parker application, Serial No. 676,463.

In the claims the terms filament and thread are employed. It is to be understood that the term "filament" is used generically, unless otherwise speeirled, to cover filaments, threads or stranwn a thread, strand or cord respectively.

Sin it is obvious that various modifications may made in the above description without depar ing from the nature or spirit thereof, this invention is not restricted thereto except as set forth in the appended claims.

I claim:

1. Vulcanized rubber products reinforced by a high'tenacity regenerated cellulose thread formed of a plurality of continuous filaments twisted together and having, throughout its length, short length fibers intertwined between said filaments and freely extending from the surface thereof.

2. A rubber tire having .a cord fabric formed of a high tenacity regenerated cellulose thread formed of a plurality of continuous filaments twisted together and having, throughout its length, short length fibers intertwined between said filaments and freely extending from the surface thereof.

FRANCIS P. ALLEB. 

